BORDETELLA VIRULENCE REGULON IN VITRO AND IN VIVO

描述(摘自申请者摘要)：BvgAS信号转导 系统协调调节波尔德氏菌涉及的基因和操纵子 感染性循环。最近的研究结果表明，波氏杆菌的毒力 监管比我们之前想象的更复杂、更有趣。 与调解两相转变相反，BvgAS似乎控制着 基因表达状态的光谱。我们还发现BvgAS调节 III型分泌物，至少部分起到调节宿主免疫的作用。 在研究BVG AS、III型分泌物和其他毒力的过程中 相关因素和表型，我们已经开发了遗传方法来 操纵波氏杆菌基因组和各种动物模型进行研究 感染和感染周期。这篇文章中概述的实验 应用程序是我们最有趣的观察结果的直接延伸 约会。它们代表了一种想要从 毒力基因调控与细菌进化的研究进展 发病机制。 在目标1中，我们将对信号进行遗传和系统发育分析 BvgAS毒力控制系统的响应性。BVG调控的基因座 显示了我们假设的明显不同的基因表达模式 反映了对差异基因表达的要求 感染性循环。我们将描述时间上和时间上的关系 空间控制的BVG调节基因的转录水平，决定是否 BVG介导的信号转导的关键特征是系统发育保守的， 并识别决定信号响应性的序列。在目标2中， BVG调节基因的转录将在体内测量并要求 对于感染周期中的差异基因表达将进行检查。 我们将检验这样一种假设，即不同的基因在不同的 呼吸道中的位置导致对特定的生态位和 既便于感染，又便于传播。目标3将重点放在 III型的调控、系统发育保守和比较功能 波氏杆菌亚种的分泌物。在目标4中，我们将使用高密度DNA 用于识别BVG调节基因的整个补体的微阵列 研究它们在感染和传播动物模型中的作用。我们 将测试BVG调节子是多相的假设 全基因组表达分析。基因表达谱差异的研究。 百日咳、副百日咳杆菌和败血杆菌也将在 了解波氏杆菌-宿主亚种特异性差异的努力 互动。

DESCRIPTION (Adapted from applicant's abstract): The BvgAS signal transduction system coordinately regulates genes and operons involved in the Bordetella infectious cycle. Recent results indicate that the Bordetella virulence regulation is more complex, and interesting, than we had previously imagined. As opposed to mediating a biphasic transition, BvgAS appears to control a spectrum of gene expression states. We have also discovered the BvgAS regulates type III secretion, which functions at least in part to modulate host immunity. In the course of studying Bvg AS, type III secretion, and other virulence associated factors and phenotypes, we have developed genetic methods for manipulating Bordetella genomes and a variety of animal models for studying infection and the infectious cycles. The experiments outlined in this application are a direct extension of our most interesting observations to date. They represent a desire to understand the biology of the bordetellae from the perspectives of virulence gene regulation and the evolution of bacterial pathogenesis. In Aim 1 we will conduct a genetic and phylogenetic analysis of signal responsiveness by the BvgAS virulence control system. Bvg-regulated loci display markedly diverse patterns of gene expression which we hypothesize reflects a requirement for differential gene expression throughout the infectious cycle. We will characterize relationships between temporally and spatially controlled transcription levels of Bvg-regulated genes, determine if key characteristics of Bvg-mediated signaling are phylogenetically conserved, and identify sequences that determine signal responsiveness. In Aim#2, transcription of Bvg-regulated genes will be measured in vivo and requirements for differential gene expression during the infectious cycle will be examined. We will test the hypothesis that differential gene expression at different sites in the respiratory tract results in adaptation to specific niches and facilitates both infection and transmission. Aim #3 will focus on the regulation, phylogenetic conservation and comparative function of type III secretion by Bordetella subspecies. In Aim 4, we will use high density DNA microarrays to identify the entire complement of Bvg-regulated genes and investigate their functions in animal models of infection and transmission. We will test the hypothesis that the Bvg regulon is multiphasic by conducting a genome-wide expression analysis. Differences in expression profiles between B. pertussis, B. parapertussis and B. bronchiseptica will also be determined in an effort to understand subspecies-specific differences in Bordetella-host interactions.